JPH0682103B2 - Visual inspection system for copper-clad wiring boards - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a copper-clad wiring board appearance inspection device for inspecting defects such as dents, scratches, and stains generated on the surface of a copper-clad wiring board.

BACKGROUND ART Conventionally, as a visual inspection apparatus of this type, one light source that irradiates the surface of a copper-clad wiring board as an inspection object with light, and regular reflection on the surface of the inspection object with respect to this light source. There is provided one provided with two light receiving portions for respectively receiving light and diffuse reflected light.

In the appearance inspection apparatus with this configuration, both light receiving parts must obtain information from the same position of the object to be inspected, so the optical axes of both light receiving parts are aligned so that they intersect on the surface of the object to be inspected. There is a problem in that this adjustment work is very troublesome. Further, even if the optical axes of both light receiving parts are slightly deviated, there is a problem in that information cannot be obtained from the same position on the surface of the object to be inspected, and accurate information on the surface state cannot be obtained. Further, an inspection object such as a copper-clad wiring board may be required to inspect a large number of items at a time, and as described above, two types of information of specular reflection light and diffuse reflection light are separately monitored. This alone cannot meet this demand.

[Object of the Invention] The present invention has been made in view of the above points, and an object of the present invention is to eliminate the need for optical axis alignment of a light receiving portion and to provide unevenness or stains on the surface of a copper clad wiring board. An object of the present invention is to provide a visual inspection apparatus for a copper clad wiring board capable of accurately detecting the above defects.

DISCLOSURE OF THE INVENTION (Structure) The present invention relates to a first light source and a second light source that irradiate light onto a copper-clad surface of an object to be inspected, which is a copper-clad wiring board, having optical axes different from each other; Is placed at a position where it can receive the specularly reflected light on the surface of the object to be inspected and the second light source to receive the diffusely reflected light on the surface of the object to be inspected. In a copper-clad wiring board appearance inspection device including a light receiving unit for converting into a signal, a blue light is emitted from a first light source, a blue light is emitted, and a second light source emits a mixed color of red and green. Color recognition that identifies the color of the surface of the object to be inspected based on the output of the light receiving elements corresponding to red and green by providing a plurality of light receiving elements that receive red light and green light independently Section, the color identified by the color recognition section and the amount of light received by the light receiving element corresponding to blue. In which the type of the surface condition of the object to be inspected is provided a fractional determination unit combined.

According to this configuration, since the surface state of the copper-clad surface of the copper-clad wiring board is detected by the two light sources and the one light-receiving section, it is not necessary to align the optical axis of the light-receiving section, and moreover, with respect to the light-receiving section. The light source that makes diffuse reflected light incident is a mixed color of red and green, and of course it can be separated from the blue of specular reflected light at the light receiving part. The state of can be identified. In this way, by recognizing the color of the surface of the object to be inspected, color information can be used in addition to the combination of two types of information of specular reflection light and diffuse reflection light, and inspection can be performed at once. It is possible to increase the number of inspection items that can be performed. Moreover, since the color is identified by using the mixed color of red and green, it is particularly suitable for the inspection of the copper clad wiring board.

(Example) As shown in FIGS. 1 and 2, a first light source 10a and a second light source 10b are provided, and each of the light sources 10a and 10b is a straight tube lamp 11a and 11b. A linear light source including the reflectors 12a and 12b and the filters 13a and 13b.
The a and 11b emit white light. The first light source 10a and the second light source 10b are arranged so as to be substantially parallel to each other. The inspection object 1 is a copper-clad wiring board and moves in a direction substantially parallel to the first light source 10a and the second light source 10b. The optical axis of the first light source 10a is inclined by an angle θ with respect to the surface of the inspection object 1, and the optical axis of the second light source 10b is arranged so as to be substantially orthogonal to the surface of the inspection object 1. It is set up. In addition, the filter 13a of the first light source 10a is set to transmit blue light, and the filter 13b of the second light source 10b is set.
Is set to transmit a mixed color of red light and green light.

On the other hand, a light receiving unit 20 is provided on the opposite side of the first light source 10a with the second light source 10b interposed therebetween. The light receiving section 20 includes light receiving elements 21 _R , 21 for receiving red light, green light, and blue light, respectively.
Color image sensor with a large number of _G and 21 _B arranged in a straight line 2
It is 1 and outputs an electric signal according to the amount of received light of each color. The light receiving section 20 is thus formed in a straight line, its direction is substantially parallel to the first light source 10a and the second light source 10b, and the optical axis of the light receiving section 20 is not covered. It is inclined by an angle θ with respect to the surface of the inspection object 1. Here, the optical axis of the first light source 10a and the optical axis of the light receiving unit 20 may be arranged so as to approximately satisfy the above relationship, and since the light flux from the first light source 10a diffuses to some extent, The light receiving section 20 can always receive the specularly reflected light from the first light source 10a. Further, since the optical axis of the second light source 10b is substantially orthogonal to the surface of the inspection object 1, the light receiving section 20 receives the diffuse reflected light of the second light source 10b. Even if the optical axes of the first light source 10a and the second light source 10b are not completely adjusted, the focus position of the light receiving unit 20 is substantially aligned with the surface of the inspection object 1 here. Since the specularly reflected light and the diffusely reflected light are received by the light receiving section 20, strict optical axis alignment as in the conventional case is unnecessary. As described above, an electric signal corresponding to the specular reflection light is obtained from the blue light receiving element 21 _B , and the red light and green light receiving elements are received.
From 21 _R and 21 _G , an electric signal corresponding to the diffuse reflection light can be obtained.

The electric signal obtained as described above is input to the signal processing unit 30, as shown in FIG. In the signal processing unit 30,
Upon receiving the red, green, and the signal R corresponding to the blue, G, and amplifier circuit 31 _R, 31 _G, 31 _B for amplifying each B, and the output of the amplifier circuit 31 _R, 31 _G, corresponding to the red and green Color recognition part 3 for identifying colors
2 and the output of the color recognition unit 32 and the output of the amplification circuit 31 _B corresponding to blue, the determination unit 33 that determines the surface state of the inspection object 1.
And the determination unit 33 can determine 6 states. That is, the following determination can be made based on the output of the light receiving unit 20.

However, in the above table, 1 is a change in the bright direction with respect to the normal part, 0 is a change in the dark direction with respect to the normal part,
φ indicates that the change in the bright direction and the change in the dark direction are mixed with respect to the normal portion.

As described above, the surface state of the inspection object 1 can be known according to the states of the specular reflection light and the diffuse reflection light, and the specular reflection light and the diffuse reflection light are distinguished by color, Moreover, by using two colors for the diffuse reflection light, the inspection object 1
The state of the color of the surface can be identified, and the number of classifications of the surface state of the inspection object 1 can be increased. A first light source and a second light source for irradiating the copper-clad surface of the inspection object, which is a copper-clad wiring board, with light beams different from each other, and a surface of the inspection object for the first light source. A copper clad having a light receiving portion arranged to receive the specularly reflected light and to receive the diffusely reflected light on the surface of the object to be inspected with respect to the second light source and convert a change in the amount of received light into an electric signal. In a visual inspection device for a wiring board, blue light is emitted from a first light source, a mixed color of red and green is emitted from a second light source, and blue light, red light and green light are independently received. A plurality of light receiving elements are provided in the light receiving section, and a color recognition section for identifying the color of the surface of the object to be inspected based on the outputs of the light receiving elements corresponding to red and green, and the color recognized by the color recognition section and the blue color. The type of surface condition of the object to be inspected A determination unit for determining classification is provided, and since the surface state of the copper-clad surface of the copper-clad wiring board is detected by the two light sources and one light-receiving unit, the signal processing unit can still recognize the pattern. By doing so, it becomes possible to recognize the pattern formed on the surface of the inspection object 1. In this case, it goes without saying that it is possible to include color information.

EFFECTS OF THE INVENTION As described above, the present invention provides a first light source and a second light source which have different optical axes and irradiate the surface of an object to be inspected with light, and the first light source to be inspected. A light receiving portion which is arranged at a position where the specularly reflected light on the surface of the object can be received and the diffusely reflected light on the surface of the object to be inspected can be received by the second light source, and which converts the change in the received light amount into an electric signal. And a light ray emitted from the first light source and a light ray emitted from the second light source include different identification elements, and an electric signal for the reflected light received by the light receiving unit is based on the identification element. A signal processing unit that outputs information according to the surface state of the inspection object by processing the electric signal for the first light source and the electric signal for the second light source separately.
Using two light sources and one light receiving unit, the light receiving unit detects information about specular reflection light and diffuse reflection light emitted from both light sources and reflected on the surface of the object to be inspected, and this information is detected by the signal processing unit. Since the surface condition of the object to be inspected is detected from, the light beam emitted from the first light source and specularly reflected on the surface of the object to be inspected can be received by the light receiving section, and is emitted from the second light source to the surface of the object to be inspected. 3 so that the light beam diffusely reflected can be received by the light receiving unit.
If the positional relationship of the person is roughly set, there is an advantage that the surface condition of the object to be inspected can be accurately detected by only rough adjustment without performing strict adjustment as in the conventional case.

Moreover, the light source for making diffuse reflected light incident on the light receiving section is a mixed color of red and green, and it is of course possible to separate it from the blue of regular reflected light at the light receiving section. The color condition of the copper-clad surface of the plate can be identified. Thus, by recognizing the color of the surface of the object to be inspected, it is possible to use the color information in addition to the combination of the two types of information of the specular reflection light and the diffuse reflection light. It has an advantage that the number of inspection items that can be inspected can be increased. Moreover, since the color is identified by using the mixed color of red and green, there is an advantage that it is particularly suitable for inspection of a copper clad wiring board.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration showing an embodiment of the present invention, FIG. 2 is a perspective view showing a schematic configuration of the same, and FIG. 3 is a block diagram showing a signal processing circuit used in the same. 1 is an object to be inspected, 10a is a first light source, 10b is a second light source, 20
Is a light receiving unit, 21 is a color image sensor, 21 _R , 21 _G and 21 _B are light receiving elements, and 30 is a signal processing circuit.

Claims (2)

[Claims] 1. A first light source and a second light source which have different optical axes and irradiate light onto a copper-clad surface of an object to be inspected, which is a copper-clad wiring board.
And a first light source for receiving specularly reflected light on the surface of the object to be inspected and a second light source for receiving diffusely reflected light on the surface of the object to be inspected. In a visual inspection apparatus for a copper clad wiring board, comprising: a light receiving unit for converting a change in the amount of received light into an electric signal, a first light source emits blue light and a second light source emits a mixed color of red and green. In addition, a plurality of light receiving elements that receive blue light, red light, and green light independently of each other are provided in the light receiving unit, and the surface of the object to be inspected based on the outputs of the light receiving elements corresponding to red and green. A color recognition section for identifying a color and a determination section for discriminating the type of the surface state of the object to be inspected by combining the color identified by the color recognition section and the amount of light received by the light receiving element corresponding to blue are provided. A visual inspection device for copper-clad wiring boards, which is characterized in that 2. The first light source and the second light source are linear light sources and are arranged substantially parallel to each other, and the inspection object moves in a direction substantially orthogonal to the first light source and the second light source, The light receiving unit is a color image sensor in which a plurality of light receiving elements that receive blue light, red light, and green light independently of each other are arranged on a straight line substantially parallel to the first light source and the second light source. The appearance inspection device for a copper-clad wiring board according to claim 1.